Implied lines are an interesting tool to improve a photo from a graphic design perspective and to encourage the viewer to move around the image in the way that you want them to. I do understand that most of these choices are unconscious on the part of the photographer, but that comes from having been concious of the technique through training such as this course.
In the two given examples the lines are dominant and immediately obvious to the viewer. The first image of the matador shows a prominent line running across the back of the bull and then continued across the shoulders of the man and then finished by his cape.
not reading the exercise thoroughly enough I didn't add arrows but the movement would be towards the top right of the image, in the direction that the bull follows.
The second image has a line running from the top of the horses head and strengthened by the eye line of the horse.
This image on the left shows a line starting from the elbow of the guitarist and running across the neck of the guitar. The direction of the implied line is from left to right, a natural direction to view an image. this direction is strengthened by the eye line of the guitarist.
The image on the right has an implied line running across the length of the stick and the dogs head. Again, the eye line of the dog creates a direction of the line from left to right. It's interesting to consider whether I subconsciously composed these images so that they would be read from left to right.
The last of my older images is of a sheep with the implied line being formed by it's back and ears.
For my "extension of a line or lines that point" I shot the fish counter at Tesco using the digital compact. I was walking around the supermarket looking for implied lines and the rows of fish paired together made an interesting line.
There is a sense of motion and direction from the shape of the fish, the line seems to point upwards, the eyes of the fish will also contribute to this effect.
To achieve an eyeline shot, I followed one of the cats around for a while to see what they looked at. This shot is interesting in that there are a few shapes that should be dominant, the square of table that can be seen, the circle of the toilet roll or the rectangle window, but the eyeline of the cat is very strong.
It may not be immediately obvious here, but I selectively coloured the eyes of the cat to see if it increased the strength of the line and it worked well. I also did it to see how well I could edit JPEGs from the new compact.